Method of providing 911 service to a private branch exchange

ABSTRACT

A method of providing 911 service to a private branch exchange, includes grouping a plurality of private telephone numbers into a set. An outgoing telephone line for a 911 call is assigned to the set. A location information for the outgoing telephone line is input into a location database.

FIELD OF THE INVENTION

[0001] The present invention relates to generally to the field of 911emergency service systems and more particularly to a method of providing911 service to a private branch exchange.

BACKGROUND OF THE INVENTION

[0002] A Public Safety Answering Point-(PSAP) uses an automatic locationidentification (ALI) information provided with the automatic numberidentification (ANI) to determine the location of a 911 telephone call.Unfortunately, when a 911 call is placed from a business having a PBX(Private Branch Exchange), the PSAP only receives the billing address ofthe business. For large businesses having multiple locations, this doesnot provide any useful information. Some PBX providers allow the ownersto enter in correct location information for all their lines.Unfortunately, this is time consuming and therefor rarely is done.

[0003] Thus there exists a need for a method of providing 911 service toa private telephone numbering system that is easy to setup.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004]FIG. 1 is a block diagram of public safety answering service for aprivate telephone numbering system in accordance with one embodiment ofthe invention.

[0005]FIG. 2 is a flow chart of the steps used in a method of providing911 service to a private branch exchange in accordance with oneembodiment of the invention;

[0006]FIG. 3 is a flow chart of the steps used in a method of providing911 service to a private branch exchange in accordance with oneembodiment of the invention; and

[0007]FIGS. 4 & 5 are a flow chart of the steps used in a method ofproviding 911 service to a private branch exchange in accordance withone embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0008] A method of providing 911 service to a private branch exchange,includes grouping a plurality of private telephone numbers into a set.An outgoing telephone line for a 911 call is assigned to the set. Alocation information for the outgoing telephone line is input into alocation database (E911 database). By grouping the telephone linessignificantly less information has to be input into the locationdatabase. The groups are selected to be telephone lines in a setgeographic area. For instance all the telephones on the third floor of asmall building might be grouped together. This provides emergencypersonnel with plenty of information to locate the emergency.

[0009]FIG. 1 is a block diagram of public safety answering service for aprivate branch exchange in accordance with one embodiment of theinvention. A public safety answering point (PSAP) 10 includes a switch12 connected to a SSP (Service Switching Point) 14. The switch 12triggers on incoming call and forms a location query. The location queryis set to a location database (E911 database) 16. The call and locationinformation are forwarded to one of a plurality of operators 18.

[0010] A company 20 using a PBX 22 groups private telephone linesaccording to their location. This company 20 has two locations 24, 26.Any 911 call from the first location 24 is routed over a predeterminedpublic telephone line 28. Any 911 call from the second location 26 isrouted over a predetermined public telephone line 30. The PBX isconnected to a SSP 32. A 911 call is then sent to SSP 14 and to the PSAP10. A SCP (Service Control Point) 34 is connected through an intelligentnetwork to the SSPs 14, 32. The SCP 34 may provide routing informationto the SSP 32 for 911 calls. A second company 36 also has a PBX 38. Thecompany 36 also divides its telephones into two locations 38, 40. Notethat any number of locations could be handled and the inventionencompasses more than a single PBX. A 911 call from any of thetelephones in the first location 38 are routed over a predeterminedexternal telephone line 42. A 911 call from any of the telephones in thesecond location 40 are routed over a predetermined external telephoneline 44.

[0011]FIG. 2 is a flow chart of the steps used in a method of providing911 service to a private branch exchange in accordance with oneembodiment of the invention. The process start, step 60, by grouping aplurality of telephone numbers into a set at step 62. An outgoingtelephone line for a 911 call is assigned to the set at step 64. At step66, a location information for the outgoing telephone line is input intoa location database of a telephone company which ends the process atstep 68. In one embodiment, the plurality of private telephone numbersare selected by an origination location. In one embodiment a privatebranch exchange is programmed to selected the outgoing telephone linewhen a 911 call is received from one of the plurality of privatetelephone numbers.

[0012] In one embodiment when the 911 call is dialed from one of theplurality of private telephone numbers, the 911 call is sent out overthe outgoing telephone line. The 911 call is triggered on at a serviceswitching point. A routing query is transmitted to a switching controlpoint (SCP). A routing instruction is received from the SCP. The 911call is routed to a proper PSAP. A location database is queried for alocation associated with a telephone number of the outgoing telephoneline.

[0013]FIG. 3 is a flow chart of the steps used in a method of providing911 service to a private branch exchange in accordance with oneembodiment of the invention. The process starts, step 80, by receiving a911 call at a private switch at step 82. In one embodiment, the privateswitch is a private branch exchange. A dialing telephone number isdetermined at step 84. An associated outgoing telephone line is lookedup at step 86. At step 88, the 911 call is placed over the associatedoutgoing telephone line which ends the process at step 90. The 911 callis received at a service switching point (SSP). The 911 call istriggered on and the SSP sends a query to a switching control point(SCP). A response is received that includes a routing instruction. Inone embodiment the response includes the number of the associatedoutgoing telephone line. The 911 call is routed to a public safetyanswering point (PSAP). A location query is sent to a location database.The 911 call is forwarded to an operator. A location information istransmitted to the operator.

[0014] In one embodiment, a first plurality of private telephone numbersare grouped into a first set. A second plurality of private telephonenumbers are grouped into a second set. One of a plurality of outgoingtelephone lines is assigned to the first set. A second of the pluralityof outgoing telephone lines is assigned to the second set. The locationdatabase is programmed to include a location for the one of theplurality of outgoing telephone lines and a second location for thesecond of the plurality of outgoing telephone lines.

[0015]FIGS. 4 & 5 are a flow chart of the steps used in a method ofproviding 911 service to a private branch exchange in accordance withone embodiment of the invention. The process starts, step 100, bygrouping a first plurality of private telephone numbers into a first setat step 102. A second plurality of private telephone numbers is groupedinto a second set at step 104. One of a plurality of outgoing telephonelines is assigned to the first set at step 106. A second of theplurality of outgoing telephone lines is assigned to the second set atstep 108. A location database is programmed to include a location forthe one of the plurality of outgoing telephone lines at step 110. Thelocation database is programmed to include a second location for thesecond of the plurality of outgoing telephone lines at step 112. A 911call is received at a private switch at step 114. A dialing telephonenumber is determined at step 116. At step 118 it is determined if thedialing telephone number belongs in the first set or the second set.When the dialing telephone number belongs in the first set at step 120,the 911 call is place over the one of the plurality of outgoingtelephone lines which ends the process at step 122. When the dialingtelephone number belongs in the second set, the 911 call is place overthe second of the plurality of outgoing telephone lines. The 911 call isreceived at a service switch point. The 911 call is triggered on and aquery is sent to a switching control point. A response is received thatincludes a routing instruction. The 911 call is routed to a publicsafety answering point. A location query is sent to the locationdatabase. The call is forwarded to an operator. A location informationis transmitted to the operator.

[0016] Thus there has been described a method of providing 911 serviceto a private telephone numbering system that is easy to setup.

[0017] The methods described herein can be implemented ascomputer-readable instructions stored on a computer-readable storagemedium that when executed by a computer will perform the methodsdescribed herein.

[0018] While the invention has been described in conjunction withspecific embodiments thereof, it is evident that many alterations,modifications, and variations will be apparent to those skilled in theart in light of the foregoing description. Accordingly, it is intendedto embrace all such alterations, modifications, and variations in theappended claims.

What is claimed is:
 1. A method of providing 911 service to a privatebranch exchange, comprising the steps of: a) grouping a plurality ofprivate telephone numbers into a set; b) assigning an outgoing telephoneline for a 911 call to the set; and c) inputting a location informationfor the outgoing telephone line in a location database.
 2. The method ofclaim 1, wherein step (a) further includes the step of: a1) selectingthe plurality of private telephone numbers by an origination location.3. The method of claim 1, wherein step (b) further includes the step of:b1) programming a private branch exchange to select the outgoingtelephone line, when the 911 call is received from one of the pluralityof private telephone numbers.
 4. The method of claim 1, furtherincluding the step of: d) when the 911 call is dialed from one of theplurality of private telephone numbers, sending the 911 call out overthe outgoing telephone line.
 5. The method of claim 4, further includingthe steps of: e) triggering on the 911 call at a service switch point;f) transmitting a routing query to a switching control point; g)receiving a routing instruction from the switching control point.
 6. Themethod of claim 5, further including the steps of: h) routing the 911call to a public safety answering point; i) querying a location databasefor a location associated with a telephone number of the outgoingtelephone line.
 7. A method of providing 911 service to a private branchexchange, comprising the steps of: a) receiving a 911 call at a privateswitch; b) determining a dialing telephone number; c) looking up anassociated outgoing telephone line; and d) placing the 911 call over theassociated outgoing telephone line.
 8. The method of claim 7, whereinstep (a) further includes the step of: a1) receiving the 911 call at aprivate branch exchange.
 9. The method of claim 7, further including thesteps of: e) receiving the 911 call at a service switching point; f)triggering on the 911 call and sending a query to a switching controlpoint; g) receiving a response including a routing instruction.
 10. Themethod of claim 9, wherein step (g) further includes the step of: g1)receiving the response including a number of the associated outgoingtelephone line.
 11. The method of claim 9, further including the stepsof: h) routing the 911 call to a public safety answering point; i)sending a location query to a location database.
 12. The method of claim11, further including the steps of: j) forwarding the 911 call to anoperator; k) transmitting a location information to the operator. 13.The method of claim 7, wherein step (a) further includes the steps of:a1) grouping a first plurality of private telephone numbers into a firstset; a2) grouping a second plurality of private telephone numbers into asecond set; a3) assigning one of a plurality of outgoing telephone linesto the first set; a4) assigning a second of the plurality of outgoingtelephone lines to the second set.
 14. The method of claim 13, furtherincluding the step of: a5) programming a location database to include alocation for the one of the plurality of outgoing telephone lines. 15.The method of claim 14, further including the steps of: a6) programmingthe location database to include a second location for the second of theplurality of outgoing telephone lines.
 16. A method of providing 911service to a private branch exchange, comprising the steps of: a)grouping a first plurality of private telephone numbers into a firstset; b) grouping a second plurality of private telephone numbers into asecond set; c) assigning one of a plurality of outgoing telephone linesto the first set; d) assigning a second of the plurality of outgoingtelephone lines to the second set; e) programming a location database toinclude a location for the one of the plurality of outgoing telephonelines; f) programming the. location database to include a secondlocation for the second of the plurality of outgoing telephone lines; g)receiving a 911 call at a private switch; h) determining a dialingtelephone number; i) determining if the dialing telephone number belongsin the first set or the second set; and j) when the dialing telephonenumber belongs in the first set, placing the 911 call over the one ofthe plurality of outgoing telephone lines.
 17. The method of claim 16,further including the step of: k) when the dialing telephone numberbelongs in the second set, placing the 911 call over the second of theplurality of outgoing telephone lines.
 18. The method of claim 16,further including the steps of: k) receiving the 911 call at a serviceswitching point; l) triggering on the 911 call and sending a query to aswitching control point; m) receiving a response including a routinginstruction. h) routing the 911 call to a public safety answering point;i) sending a location query to the location database j) forwarding thecall to an operator; and k) transmitting a location information to theoperator.